Today we went to take the battery out of the car to check and see the date on it and low and behold it has a sticker of 10/14. So why the heck does it keep going flat on us? I put the charger on it and got it up to 12.9 volts and put it back in the car. Drove it 25 miles and pulled into advance auto parts. They put the tester on it and said that it is fine, putting out 443 cca when it is a 600 cca battery. I can live with that as it has not trouble turning the car over when charged. They checked the alternator and it was all good as well. So it must be a constant draw. I got out the meter, removed the negative terminal and bridged the post with one lead and cable with the other. 50 milliamp constant draw. That is nothing, not even enough to light up a bulb. So the cars been sitting for a couple weeks now and just the last couple days the temps have been down in the low 30's at night. Anyone have a clue as to what could be going on? Sorry for the long rambling.

 

Maybe just a bad battery.

 

The cold cranking amps seems pretty low, being about 160 CCA lower than its rating. I believe this is the main source of the issue, with the weather contributing to this. The battery does not seem too good, despite it only being a year. Was the car kept in a very hot climate during the warmer months? Very warm climates attribute to the failure of car batteries.

For the future, I would highly recommend AGM batteries for these cars. It's what I started using recently, after my father got his a few years back. Here is a good article about them.

My father and I use the DieHard Advanced Gold AGM batteries (Group 34R). Hope this helps!

I purchased my battery here.

 

you can have a bad Cell on that battery.

 

I'll check into the agm battery. We are in Atlanta. It sits in the garage mostly as my son just got his permit. I'm thinking a weak cell causing it to lose its charge. Now that it gets driven s little more that 20 miles every three weeks maybe it will do better. With our tax return we are going to tidy up some things, hopefully the battery will hold out until then.

 

What is an AGM battery?

 

I've seen all kinds of strange things from dead or dieing batteries....including what are supposed to be "newer" batteries. I have the Optima Red Top in mine and I think it's about five years old and going strong. If your son's car isn't going to get driven much I would recommend a battery tender.

 

Quoting the article I linked, AGM batteries are:

"absorbent glass mat (AGM) batteries, as indicated. These cost significantly more than conventional batteries, but they excel in our tests. Further, they are spill-proof, usually last longer, have a low self-discharge, can better tolerate deep discharge, and stand up well to extreme temperatures. Thus, AGM batteries are especially well suited to certain conditions, such as for cars that might be parked for extended periods or vehicles with high power demands due to accessories."

Also, KJG92, 600 CCA as-is may be a little low for LS400s; I was barely making it by with 500 CCA last month, until I got the new battery. If I recall correctly, these cars originally came with batteries that had 700 CCA.

I also edited my initial post. I use a Group 34R DieHard Advanced Gold AGM battery. I purchased my battery here.

 

I had to change my battery 9 months ago and when i checked the + connection cable end, under the plastic cover that was attached to the battery it was all rusted and even cracked. I changed the connector and it is all fine now. I was having random dead batteries, since then it all fine.

Also when i bought the car from the previous owner he informed me that the cigarette lighters plugs were causing the battery to go dead. I do not let anything plugged in these overnight.

Hope my experience can help

 

How is that battery holding up?